The present invention relates to catheters and, more particularly, to improved catheters for use as embolectomy catheters and flow-directed diagnostic catheters. In its more specific aspects, the invention is directed to such catheters which employ balloons which may be expanded into a helical configuration.
It is well-known in the art to provide embolectomy catheters with annular balloon means for blood clot removal. U.S. Pat. No. 3,435,826 to Thomas J. Fogarty, one of the coinventors herein, discloses such a catheter.
It is also known in the art to provide embolectomy catheters with a wire or blade in the shape of a spiral helix. Such catheters are rotated to screw the helix into the clot, following which the catheter is removed from the blood vessel without rotation. A catheter of this type is shown in U.S. Pat. No. 4,030,503 to Clark.
Embolectomy catheters have also been provided with annular balloons having flexible protrusions adapted to bite into the clot upon inflation of the balloons to enable the clot to be pulled free by withdrawal of the catheter. Such a catheter is shown in U.S. Pat. No. 3,635,223 to Klieman.
Catheters have also been provided with successively inflatable helical balloon sections to render the catheters self-propelling. A catheter of this type is shown in U.S. Pat. No. 3,485,237 to Bedford.